Conventionally, received bit error rates are determined by one of two methods: by transmitting from time to time a known symbol pattern of sufficient length to have a high probability of at least one error, or by including an error-detecting code in the normal data and keeping a count of the errors so found. Either of these methods have the problem of requiring many bits of transmitted data to make an accurate estimate of the bit error rate. For instance, if the expected bit error rate is 1 in 100 thousand (a typical figure), an accurate estimate of the actual error rate would require the evaluation of several hundred thousand bits.
The additional system overhead bits required by either of these schemes undermines system throughput and constrains BER measurements to ensue on specific events or at specific predetermined intervals.
This invention then takes as its object to overcome these shortcomings and to realize certain advantages presented below.